Once an inherently underground expression of African-American oppression, hip-hop has all but conquered mainstream music, language and fashion. Hollywood has attempted to profit from that crossover by opening its arms to a handful of stars -- including Ice Cube, Ice T, Nas, DMX, Method Man, Queen Latifah and the late Tupac Shakur -- with varying degrees of success. But if the simultaneous arrival of the gritty-but-uneven drama Turn It Up and the raucous tour documentary "Backstage" is any indication, the true gold rush for hip-hop cinema may be ready to begin.

In many respects, the films are two sides of the same coin: the manufacturing and selling of rap music to the public. "Turn It Up" follows the efforts of talented inner-city rhymer Diamond (Pras Michel, a founding member of the Fugees) to complete a demo recording that's sure to land him a phat label contract. Diamond, known to his friends as D, is a perfectionist whose determination to nail down the details of his work is stymied by the incompetence of his cokehead engineer, Baz (Chris Messina). D is pushed to complete the project by Gage (rapper Ja Rule, making his film debut), a thuggish pal who's willing to gather the $100,000 in studio costs by any means necessary.

His girlfriend, Kia (Tamala Jones of "The Wood" and "Booty Call"), urges D to abandon his criminal lifestyle, as does his long-estranged musician father, Cliff (Vondie Curtis Hall of "Eve's Bayou" and "Crooklyn"), who's back on the scene after a 12-year absence. But the proud kid is unable to untangle himself from connections with a Manhattan drug lord named Mr. B (Jason Statham) and apparently too impatient to submit to the grind and low pay of a day job. D's debut recording turns out to be an extremely pricey project, at least in terms of its cost in human lives.

"Turn It Up" features tense confrontations, competently shot action scenes, a juicy, pumped-up soundtrack and appearances by MTV host DJ Skribble and recording artists Shinehead and Faith Evans. But its message -- that one's ability to survive long enough to make the big score is really all that matters -- is difficult to stomach.

Were D to morph into a nonfiction character, he might snag some screen time in "Backstage," a fast-paced, bawdy account of last year's Hard Knock Life Tour. Boasting galvanizing performances by many of the genre's superstars and hot newcomers (including Jay-Z, DMX, Method Man, Redman, Beanie Sigel, Memphis Bleek, Ja Rule, DJ Clue and Amil), the tour reportedly grossed $18 million and was free of violence and artist cancellations, despite the advance naysaying of some industry observers.

The performances seen here (in crowded arenas everywhere from Charlotte, N.C., to Denver to Los Angeles to icy Montreal) are often riveting. Jay-Z, toughened by a childhood in Brooklyn's tough Marcy Projects, is among the most effective, often appearing bare-chested and demonstrating reserves of charisma with his tales of the gangsta life. The fierce Beanie Sigel, a bulldog of a guy, is one of the most striking of the new stars. Resplendent in white, female rapper Amil offers a refreshing break from the testosterone-pumped personas of her co-stars.

Chris Fiore, who directed and edited the film, backs up his documentary's title with plenty of behind-the-scenes action, occasionally stumbling onto some thought-provoking interviews.

"Everybody's waiting for something bad to happen," Jay-Z sidekick DJ Scratch says about the arguably racist expectation of audience unrest. Ja Rule testifies to rap's role as an escape route, a rags-to-riches path for the most fortunate: "This music shit is a savior," he asserts. "We come from nothing."

Wannabe rappers get some exposure, including several rhymers who are probably too nerdy for the job and a pint-size fan with real talent. "I just wanna grow up and be a rap scholar," says one kid who looks all of 6 or 7 years old. Some moments are worthy of "This Is Spinal Tap," including the extended ranting and raving of Roc-A-Fella Records head Damon Dash, who is determined that his label and its artists won't be overshadowed by the Def Jam crew. After seeing the film, Dash may regret allowing Fiore such extensive access.

"Backstage" also captures the behind-the-curtain recreation that's common to big-time tours (particularly those mounted by 20-something artists on the rise). Gambling, heavy drinking, constant toking and sexual exploits with groupies -- many partially or wholly nude -- are all portrayed. For better and worse, Fiore's cameras seldom blink.

Note to the distributors of "Backstage" and "Turn It Up": Do yourselves (and your filmmakers) a favor the next time you release hip-hop-flavored movies. Check out the schedules of your competitors and avoid dropping two rap films into the multiplexes at the same time. It's not exactly a brilliant marketing strategy, even for a genre that shows every sign of, shall we say, blowin' up.